Cartrack debit without agreement

After I reported car track on helopeter 2 weeks back again they never stop debiting my account without any agreement with them, on the 15th July again they were debiting R850, on the 22nd June they debited R914, on the 23rd June they debited R914 on the 1st June they debited R914 on the 15th May they debited R914 they debited 3 times in June alone.

When I phoned them they told me they have tracking system that debit automatically when there is money in my ABSA Aaccount....

Now I have to move money to another account if I forget they will take it, I once had contract with them which was R300 monthly, after 2 months of non payment due to accident and they poor servicd they close it down and my account was reffered to attorneys but till today after 2 years they still debit my account without any agreement with them.